Implements of this general type typically include a handle with a needle along which yarn or thread can be extended. The needle is pointed at one end to facilitate its passage through the web of fabric that forms the rug backing, or embroidery foundation, etc, as the case may be. The purpose of these implements is to thereby facilitate the formation of yarn or thread loops that are then used in ways peculiar to the particular form of needle-craft under consideration.
In the case of an exemplary embroidery tool, such an implement might have a tubular needle mounted in outwardly extending relation from the end of a graspable handle. The handle is hollow and communicates interiorly with the hollow tubular needle, so as to accommodate the passage of thread from an opening in the opposite end of the handle, through the interior thereof, and into the interior of the tubular needle. A lateral opening or "eye" extending through the tubular wall of the needle, proximal to the end thereof that is furthest removed from the handle, is adapted to pass the thread from the interior of the needle, to the exterior thereof.
In any case, it will be appreciated that the size of the loop formed upon each passage of the needle through the web of fabric, will be determined by the distance beyond the opposed web surface that the needle extends. From the aesthetic point of view, uniformity of loop size is highly desirable. To this end, a number of attempts have been made to adjustably limit the extent to which the needle is free to penetrate the web. In one approach, small sleeves are provided with the implement. These sleeves are adapted to fit in secure frictional engagement over the outside of the tubular needle, and to abut against the fabric web once the needle has advanced to the limit of its intended penetration through the web. The sleeves are available in a variety of different lengths, to provide the user with an option in selecting various, corresponding loop sizes. For a number of reasons, this arrangement is not desirable. Firstly, the sleeves are separate pieces that can be easily lost, or at least frustratingly misplaced. Secondly, fitting the sleeve over the tube requires manual dexterity and close attention, if one is to avoid undesired contact with the pointed end of the needle.
Accordingly, a number of adjustment mechanisms have been developed in which provision has sought to have been made for adjustably locating the needle along the axis of the holder. This is done so that the holder in effect provides an adjustable means for abutting against the fabric web. In this way there is provided a selectively consistent, passive limit on the distance the needle travels through the web on each stroke. An example of one such device is set out in U.S. Pat. No. 4,479,445, while another is disclosed in U.S. Pat. No. 4,306,510.
One objection to such prior art devices is that they can, over time, become easily maladjusted in the course of normal use. Moreover, their infinite variability of positioning is neither necessary for the purposes of needle-craft nor, from the point of view of the user wishing to duplicate a previous adjustment setting, even desirable. In addition, the required rotational adjustment is both tedious, and in some cases may even be positively irritating to sufferers of such debilitating conditions as arthritis or carpal tunnel syndrome. This short-coming is especially pronounced when the needle must be withdrawn and re-extended for and following use, (as is done in the interests of safety and for the protection of the needle from physical damage when not in use). Finally, the indexing marking can also be very demanding on a user's visual acuity.
There remains a need in the art, therefore, for an adjustable needle-craft implement which facilitates easily reproducible adjustment settings, that can be accomplished without taxing the physical or visual abilities of expected users, while at the same time positively locking the needle at the desired setting so that any need for repeated readjustment during normal use, is substantially reduced. Moreover, it is highly desirable from a safety point of view that the needle be amenable to ready and convenient retraction/extension relative to the barrel of the implement, in order to encourage users to handle and store their implements safely.